Here are a few of the astonishing facts Henry Louis Gates Jr. brings to our attention in his new book:

Nearly 8 million white Americans have hidden African heritage. That means one of their foremothers or -fathers within the last six generations would be classified as African American if the "one-drop rule" were still enforced. It also means somebody in their family in the last 200 years was technically black and managed to pass for white.

Some African Americans owned enslaved people, and those they owned were not all relatives. To be sure, these slaveholders were a tiny percentage of the total number of free blacks (about 1 percent of free blacks owned just six-tenths of 1 percent of the total number of enslaved people). Most owned just one slave, but about 50 owned between 20 and 84 slaves in 1830.

Civil rights figure and baseball great Jackie Robinson was court-martialed three years before he joined Major League Baseball. He refused to move to the back of a near-empty military bus and was arrested but not convicted of "behaving with disrespect toward . . . his superior officer." Had he been convicted, our history might look different.

It's a fun book that, in no particular order, asks and answers questions about ancient history (Balthasar, one of the three wise men, was the first black person to see Jesus), Afro-European history (Russian Emperor Peter the Great had an African godson, Abram Gannibal), and Afro-Latin history (Argentina deliberately sought to wipe out its black population as a "policy of covert genocide"). It brims with conversation pieces but also with the pain of the lives of enslaved people of African descent here and around the world.

Did dogs actually eat enslaved people? Yes, according to Fact 15. Were any slave rebellions successful? No, according to Fact 29. There is also a fair representation of firsts, such as the first black woman to become a millionaire (Sarah Breedlove, later known as Madam C.J. Walker), the first black man to serve in the U.S. Senate (Mississippi Republican Hiram Revels), and black folks in unexpected places: serving as marshals in the Wild West, dying on the Titanic.

A subtle, insistent point throughout is the indelible impact of people of African descent from ancient history to the present. The discussion of whites with hidden African history reminds us of how intertwined we all are. Indeed, those who declare that "white lives matter" might find their white has a bit of black in it.

Julianne Malveaux is an economist and writer. This review originally appeared in the Washington Post.